RE: Default Currency for my company
NO - PLEASE DO NOT CREATE IT!
Please don't add your local currency to the currency list.
If it is ever set on vendors/customers/banks, you post transactions and it has an exchange rate you will really mess up your books.
It is very hard to clean up after such an error - so please NEVER add a local currency to the currencies list!!!
Always us a blank/empty currency when you deal with local currency (LCY) and define which one it is on the General Ledger Setup page.
Again: PLEASE NEVER ADD IT AS A CURRENCY! :-)